diff --git a/backup.sh b/backup.sh
index ff582c8..42ab58c 100755
--- a/backup.sh
+++ b/backup.sh
@@ -16,9 +16,9 @@ set -euo pipefail
 
 BACKUP_DIR="${1:-./backups}"
 GPG_RECIPIENT="${2:-}"
-DB_NAME="${DB_NAME:-mcp}"
-DB_USER="${DB_USER:-postgres}"
-DB_HOST="${DB_HOST:-localhost}"
+DB_NAME="${DB_NAME:-bossai}"
+DB_USER="${DB_USER:-ubuntu}"
+DB_HOST="${DB_HOST:-/var/run/postgresql}"
 DB_PORT="${DB_PORT:-5432}"
 RETENTION_DAYS=7
 
@@ -30,7 +30,7 @@ COMPRESSED="$DUMP_FILE.gz"
 
 echo "[$(date)] 开始备份: $DB_NAME@$DB_HOST:$DB_PORT"
 
-# 1. pg_dump 导出
+# 1. pg_dump 导出(通过 unix socket peer auth,无需密码)
 if pg_dump -h "$DB_HOST" -p "$DB_PORT" -U "$DB_USER" -d "$DB_NAME" -f "$DUMP_FILE"; then
     echo "[$(date)] 导出成功: $DUMP_FILE"
 else
@@ -71,6 +71,7 @@ cat <<EOF
   gunzip bossai_XXXXXXXX_XXXXXX.sql.gz
   # 恢复
   psql -h $DB_HOST -p $DB_PORT -U $DB_USER -d $DB_NAME < bossai_XXXXXXXX_XXXXXX.sql
+  # 注意:在服务器上执行(ubuntu用户),本地无法连接数据库
 
 EOF